Ash remover for underfeed stokers



ASH REMOVER FOR UNDERFEED STOKERS Filed March 2l, 1932 2 SheebS-Sheel'll /fw/E/v TUR T. H. BANHELD '-EVWWM.

/4 7' TURA/E June 7, 1938. T. H. BANFIELD ASH REMOVER FOR UNDERFEEDSTOKERS 2 Sheets-Sheet 2 Filed March 2l, 1932 /qTraR/VE A Patented June7, 1938 PATENT .ol-Fics N Asn aEMovEa Foa UNDERFEED s'roKEas Thomas H.Banfield, Portland, Oreg., assignor to Iron Fireman ManufacturingCompany, Portlana, oreg.

Application March 21, 1932, Serial No. 600,193

5 Claims.

This invention relates generally to underfeed stokers, and particularlyto ash removers therefor.

The main object of this invention is the pro vision of a simple andemcient form of ash remover wherein the ashes are removed from Atheunder side of the burning fuel as distinguished from those types of ashremoverswherein the ashes pass over the top of an outer rimintoacollector of some sort.

The second object is to produce an ash remover which will removeunclinkered fine particles before they can be subjected to heat for asufficient period to reduce them to linker form which would otherwiserequire a breaking up of the clinkers before they could be successivelyhandled by any ordinary conveying apparatus.

The third object is to reduce the quantity of hard clinkers formed andin many cases eliminate the hard clinker altogether, depending entirelyupon the kind of fuel being employed, the rate of burning and otherfactors which enter into the combustion.

These, and other objects, will become more apparent from the specicationfollowing as illustrated in the accompanying drawings, in which:

Fig. 1 is a vertical section through the device.

Fig. 2 is a section taken along the line 2-2 in Fig. 1. p

Fig. 3 is a plan of device shown in Fig. 1 at a reduced scale.

Fig. 4 is a plan of Yan alternative form of the device.

Fig. 5 is a section taken'on the line 5-5. of Fig. 4. I Y

Fig. 6 is a fragmentary side elevation taken on the line 6-6 of Fig. 5with the ash discharge chute removed.

Similar numbers of reference refer to similar parts throughout theseveral views.

Referring in detail to the drawings, there is shown the end of thecommon form of fuel feed duct il which discharges into a` retort sectionIl through which extends the shaft |2v ofthe feed screw I3 disposedwithin the duct I0. Upon the retort section is mounted a tuyre sectionIl provided with air outlet openings i5, I6, I1 and Il.

Supported on the brackets |9 is a circular tabl 2l upon which rides theash remover ring 2| which is provided with a plurality of pockets 22.Rollers 23, carried by the ring 2|, ride against the outer wall 24 ofthe tuyre section I4. 'I'he wall 2l is provided with an out-turned rim25 which projects over the top of the inner edge 2B of the ring 2|. Itwill be seen that the ash ring- 2| in effect constitutes a rotatablebase forthe fire pot.

The table 20 is provided with an opening 21 5 through which ashes 28 canfall whenever one of the pockets 22 of the ring 2| is brought intoregister with the opening 21. After the ashes leave the opening 21 theyenter a collector chute 29 from which they are disposedof in any de- 10sired manner. Resting upon the outer rim of the table 20 is a re pot rim30 preferably made of a refractory material.

Secured against the outer walls 3| and 2l isa bracket 32 which carries astud 33 on which 15 is mounted a pinion 3l which, in this instance, isshownas the driven element of a Geneva escapement. The pinion 34 mesheswith the teeth 35 which are formed on the depending. flange 36 of thering 2|. A driving gear 31 is mounted 20 on the outer end of the shaftI2 and meshes with the pinion 34. A

The operation of this form of the devicev is as follows: As ashes areformed and pass over the top of the tuyre section I4 onto the ring 2 I,that 25 is, to the lowermost portion of the outermost zone of vthealmost completely burned fuel, they are subjected to the intermittentmotion of the ash remover ring 2l which gathers its pockets full of fineunclinkered residue which it empties 30 successively through the opening21 in to the discharge chute 29.

It can be seen from the foregoing that the ilne ashes on the ring 2| areremoved soon after they are formed, remaining in the presence of 35 theintense heat only a short space of time, which need not be sulcient tofuse them to clinker form which would make same more dimcult to bedisposed of. Furthermore, with this construction even those partiallyformed clinkers which find their way into the pockets 22 are veryfragile and are easily crushed by the shearing action occurring betweenthe table 20 and the ring 2| whenever a pocket 22 passes out of reg- 5ister with the opening 21.

With the form of the device shown in Figs.

4, 5 and 6 the table 381s imperforate and sta- 'tionary and carries onits top surface the ash remover ring 29 which is provided with the out-50 wardly projecting teeth Il, which latter extend to the upturnedflange 4| of the. table Il. The. flange 4| is provided. with an outlet42 beneath which is the ash disposal chute 43. The ring 39 has adownwardly extending flange M having widely spaced teeth 45 formed onthe under side vthereof.

In this form of the device the feed screw shaft I2 is employed to drivean arm which engages the successive teeth 45 in its rotation about theshaft I2,'imparting to the ring 39 an intermittent rotary motion.

The only difference in theoperation of this form of the device from theone previously described is that the teeth lll move the ashes. 2l

` outwardly radially beyond the edge of the table 38 instead ofpermitting them to drop through an opening in the table.

I claim:

1. A coal burning stoker having in combination a circular tuyre section,a fire pot surrounding said tiwre section and spaced therefrom, a tablewithin said space below the top of said repot and tuyre sections andspaced from said tuyre section, said table having an outlet for ashesaccumulating thereon, a rotatable ash remover ring mounted on said tableand having openings therethrough whereby ashes accumulating therein willbe carried around said table at the bottom of the outer portion of thefuel bed and discharged therefrom into said outlet, said tuyre sectionhaving an encircling flange immediately overlying the top inner edge ofsaid ring, `a ring gear within the space between said' table and tuyre,and a pinion actuated by the fuel feed screw of the stoker meshing withsaid gear.

l 2. A coal burning stoker having in combination concentric tuyre andfire pot sections spaced from each other with a table supported in saidspace below the upper portions of said fire pot and tuyre sections, saidtable being spaced from said tuyre section, said table having an outletat one side thereof, a rotatable ring forming. an annular extension forthe fuel supporting surface of the stoker and mounted on said table andhaving pockets therethrough adapted to collect ashes and carry samearound said table and to discharge said ashes from the opening thereof,said ring having a downturned central flange projecting through thespace between said table and tuyre section, said flange having gearteeth on its lower edge. and a drive pinion meshing with said gear.

3. In an underfeed -stolzer employing a fuel feed screw and having aretort crowned by a circular tuyre section, an ash remover comprising atable disposed around the tuyre section below the upper edge thereof,said table constituting the outer portion of the fuel engaging surfaceof the stoker, said table having an outlet opening therein, an ashremover ring having openings therethrough for collecting ashes andtransporting same around said table to its outlet opening, said ringhaving a downturned geared flange projecting below said table, a pinionsupported by said tuyre section meshing with said flange and driven bythe fuel feed screw of the stoker, and a chute for carrying ashes fromthe table opening.

4. An underfeed stoker having in combination a horizontal'fuel feed ductterminating in an upwardly discharging retort, a fuel feed worm forconveying fuel through said duct, said worm having its drive shaftprojecting through the side of said retort, a circular tuyre sectionmounted on said retort. a perforated table surrounding said tuyresection and spaced therefrom, a rotatable ring mounted on saidtablehaving a flange gear projecting downwardly from its inner edge throughthe -space between said table and tuyre section, a gear driven by saidworm shaft and driving said rotatable ring, anda chute under theperforation in said table whereby the ashes discharging therefrom willbe deflected away from said gears.

5. In an underfeed stoker mechanism for furnaces incorporating a tuyre,the combination with a ilre pnt extending upwardly from the tuyre and afuel feeding screw conveyor mechanism, of a rotatable ring having ashreceiving cells therein carried by the stoker mechanism and actuated bythe screw conveyor mechanism, and a base plate supporting the rotatablering and having an ash outlet orifice therein with which the cells inthe ring successively communicate.

THOMAS H. BANFJELD.

